Apparatus for taking samples of liquid

ABSTRACT

Suction apparatus for taking samples of liquid such as blood. A receiving tube is provided with an axially slidable piston including a perforable resilient partition, and a support rod, carrying a hollow needle connected to a suction tube, is insertable into the open end of the receiving tube, so that the needle when the support is inserted in the open end perforates the partition and places the space beyond the piston in communication with the suction tube. Interengagement of the support and piston prevents the piston moving relative to the support, when the support is moved relative to the receiving tube. More than one rod may be provided on a common suction duct.

[451 Oct. 10,1972

United States Patent Sausse mb Tm U mm .1 0C 800 66 99 Mn 40 1 [54]APPARATUS FOR TAKING SAIVIPLES OF LIQUID [72] Inventor:

Andre Sausse, Sceaux, France Primary Examiner-Richard A. GaudetAssistant Examiner-J. G. McGowan Attorney-Stevens, Davis, Miller &Mosher Oct. 10, 1969 [57] ABSTRACT Suction apparatus for taking samplesof liquid such as [30] Forelgn Apphcatlon Pnomy new blood. A receivingtube is provided with an axially slidable piston including a perforableresilient parti- Oct. 10, 1968 France....................68169501' tion,and a support rod, carrying a hollow needle con- [52] US. Cl...............l28/2 F, l28/DIG. 5, 128/220,

nected to a suction tube, is insertable into the open end of thereceiving tube, so that the needle when the 128/276, 128/278 [51] Int.Cl. 5/14, A61m l/OO 128/2, 214.2, 218, 220, 237,

support is inserted in the open end perforates the partition and placesthe space beyond the piston in com- 278 munication with the suctiontube. lnterengagement of the support and piston prevents the pistonmoving [58] Field of Search.......

[56] References Cited relative to the support, when the support is movedw m d m e n o n w a r. ht tm w m E On g M m .m .w u a bS m mn go 7 .mm V0 a m ea C a d 0 a e e ew .wm m0. e mb N m 82 W J2 "I m J Am w m m TSAOS T s 37 @610 Tww l NWn v U 1 PATENTEU E 10 I97? 3 696, 8 O6 SHEET 1BF 3 PATENTEDncI 10 I972 SHEET 2 [IF 3 APPARATUS FOR TAKING SAMPLESOFLIQUID The present invention relates to apparatus for taking samplesof liquid, such as blood.

Blood is taken from human beings for therapeutic or diagnostic purposes,and for the latter purposes analytical laboratories now very oftenrequire to be supplied with a number of separate samples, generally fromthree to five samples, in order to be able to study separately theserum, the plasma and the cellular elements.

The device most commonly employed for taking blood consists of a hollowpuncture needle provided with a tin by which it can be gripped andwhich'is con nected to a withdrawal tube. The puncture needle isintroduced into the patients vein, generally a vein in the bend of theelbow, and the blood is caused to flow directly into the withdrawal tubeunder the action of the venous pressure, if necessary increased by theapplication of a tourniquet. This device is ,not very suitable forfilling a number of tubes, because it is difficult to avoid spilling theblood when changing the tube, since the flow of blood cannot beinterrupted.

Blood-taking devices are known in which the puncture needle is mountedon a syringe. It is possible by means of these devices to withdraw thenecessary quantities of blood and to distribute them in a number ofsampling tubes. These devices must be delicately manipulated and theynecessitate the use of both hands, and it sometimes happens that theneedle is moved out of the vein or that the latter is pierced through.

In order to obviate these disadvantages, devices have been proposed,which are generally only intended to be used once, and which comprisewithdrawal tubes closed by a stopper in which a vacuum has beenestablished. In the taking of blood, the puncture needle is placed incommunication with each of the two evacuated tubes, for example byperforating the stopper. The blood immediately fills each of the tubes.However, the maintenance of the vacuum is uncertain and the blood may bemodified at the beginning of the taking of the sample by the suddenevacuation or by the throttling consequent upon the vigorous suctionthrough the needle and the withdrawal tube,which may also result incollapse of the vein.

According to the present invention there is provided suction apparatusfor taking samples of liquid, such as blood, such apparatus comprising areceiving tube having an open and a closed end, a, piston axiallyslidable in the receiving tube and having a perforable resilientpartition, a support rod insertable within the open end of the receivingtube having a suction tube connected thereto, a hollow needle mounted onthe support rod and connected to the suction tube and positioned, whenthe support rod is inserted in the open end of the receiving tube, so asto perforate the partition and place the space between the piston andclosed end of the receiving tube, in communication with the suctiontube, and interengaging means on the support rod and piston to locatethe piston relative to the support rod, when the latter is insertedwithin the open end of the receiving tube.

Such apparatus is simple and is suitable for single use, it isconvenient to handle and is suitable for taking one or more separatesamples of liquid, notably of blood, successively or simultaneously, anddoes not exert any violent action on the liquid sample.

In order that the invention may be more readily understood, thefollowing description is given, merely by way of example, referencebeing made to the accompanying drawings, in which FIG. 1 is aperspective view of the support of one embodiment of apparatus accordingto the invention;

FIG. 2 is a view similar to FIG. 1 of the receiving tube forco-operating with the support rod of FIG. 1;

FIG. 3 is a sectional view of the piston which is slidable in thereceiving tube;

FIG. 4 is an elevation, partly in section, of a modified form ofapparatus; and

FIG. 5 is a perspective view of a box holding the receiving tubes toco-operate with the support rods of the apparatus of FIG. 4.

FIG. 6 is a fragmentary longitudinal section of an embodiment of theinvention showing the support and receiving tube assembled together; and

FIG. 7 is a perspective view of a modified form of the receiving tube.

The apparatus illustrated in FIGS. I, 2 and 3 is composed of acylindrical receiving tube 1 having a flat or rounded closed end. Thereceiving tube 1 contains a piston 2 which closes the tube influid-tight manner and is adapted to slide with gentle frictionalongalmost the whole length of the tube. The piston 2 is provided witha perforable resilient partition 15, and its forward face is formed witha circular groove 3, the piston being disposed in the receiving tubewith its forward face directed towards the open end of the receivingtube. In use, the receiving tube, thus provided with the piston, isfitted on to a substantially cylindrical support in the form of asupport rod 4 of approximately the same length as the receiving tube. Tofacilitate handling, the support is provided with a base 5. Extendingthrough the support is a duct 6 which passes through the base and isconnected by means of an appropriate end member 7 to a suction tube 9,which, as illustrated, is connected to a puncture needle 8. The duct 6receives at its opposite end a hollow needleglfl capable of perforatingthe partition 15 of the piston. The support 4 is hollow over a portionbetween one-quarter and ninetenths of its total height and preferablybetween onethird and two-thirds of its total height.

The lateral wall thus freed is formed with one or more slots 11; two tofive longitudinal slots are suitable, but it is preferred to providethree slots, as shown. Axially extending arms 12 thus formed in the wallof the support are flared at their ends, which may be done, for example,by pulling them laterally outwards beyond their elastic limit so thatthey remain deformed.

At their ends, the arm 12 are formed with an internal rib 13, the upperedge of which is frusto-conical and the dimensions of which are such asto enable it to interengage with the circular groove 3 in the piston 2.

' The ribs thus constitute jaws which can engage the from leaving thetube. The lugs are generally equal in number to the slots 11 and aredistributed in the same manner so that they may move within the saidslots: The lugs are so profiled that the piston can readily beintroduced into the receiving tube and retained therein.

In operation, before the sample is taken, the receiving tube providedwith the piston is fitted on to the support, the piston being maintainedpartly within the receiving tube by the ends of the jaws 12. At the timeof use, the operator pushes the tube on to its support until the pistonabuts the closed end of the tube, the effect of which is to force thehollow needle through the piston so that it pierces the partition andengages the jaws in the groove 3. Any air remaining at the bottom of thereceiving tube is thus expelled through the duct 6.

The apparatus is then ready to take the sample. In the case of thetaking of blood, the operator introduces the puncture needle into thepatients vein and then slowly withdraws the receiving tube from thesupport. Since the piston is located with respect to the support by thejaws, it slides along the receiving tube towards its open end, wherebythe blood is sucked into the-space defined between the closed end of thetube and the piston, thus gradually freed, as in a syringe.

When the piston reaches the open end of the receiving tube, the jawswhich-have until then been maintained slightly compressed within thereceiving tube by its lateral walls are freed and, in expanding, moveapart andout of the groove in the piston. Since the latter is no longerpulled by the support, it remains at the end of the receiving tube,which is thereby maintained closed in fluid-tight manner. The pistonthen performs the function of a plug,,since the needle 10, which isfixed to the support has simultaneously been withdrawn from the pistonand the hole which it made therein is reclosed on itself. The lugs causethe piston to remain within the receiving tube despite any faultymanipulation.-The receiving tube, thus filled with blood and closed influid-tightmanner, is then immediately available to the analyticallaboratory, where either it is directly placed in a centrifuge or anywithdrawal needle of known type may be fitted thereto.

It is particularly desirable to be able to employ the piston slidingwithin the receiver first as the piston of a syringe and then as a plugwhich is automatically positioned, without the operator having to changehis action. Owing to this particular feature, this'apparatus isextremely convenient to use.

This apparatus is even more advantageous when a number of separatesamples are to be taken. FIG. 4 illustrates a construction of theapparatus according to the invention by means of which three separatesamples may be taken.

A puncture needle 8 is, for example, directly fitted without anintermediate flexible tube on to an end member 7 laterally secured tobase 5 common to three identical supports 4. Mounted on each support isa receiving tube providedwith its piston as in FIG. 2 and 3. A commonduct 6a connects the punctu're needle to each of the receiving tubes. Itwill be appreciated that such a device can be particularly readilyemployed since when the needle has been introduced into the patientsvein, the operator, holding the withdrawal device at its base in onehand, has only to withdraw by the other hand, either successively orsimultaneously as desired, the three receiving tubes which areautomatically stoppered after having been filled.

Advantageously, a detachable member, for example a jack,,is provided forthe simultaneous withdrawal of the receiving tubes.

Of course, modifications may be made to this device. For example in FIG.6, a hollow needle 10 pointed at both ends may be secured to an endmember 20 which is force-fitted on the piston. The hollow needle thuspermits of drawing samples into the interior of the receiving tube. Asecond resilient partition 22 then closes the end of the duct 6 of thesupport 4. With this arrangement, a number of samples can besuccessively taken without any escape of blood. Also, the lugs may beprovided, not directly on the receiving tube, but on a memberindependent of the tube, for example on a ring 24 fitted around thereceiving tube at its open end as shown in FIG. 7. If the receiving tubeis intended to be used only once, the member provided with lugs may bereused. The suction tube may be employed directly or it may be connectedto a probe, or to a puncture needle. Any desired number of receivingtubes may be arranged in parallel, this number generally being limitedto five. The ducts may be provided, as illustrated, with non-return ballvalves 16, notably in the case where a number of samples aresuccessively taken. The simultaneous handling of a number of receivingtubes may be facilitated by appropriate means, for example by disposinga set of receiving tubes in a closed protective box. Such a box isillustrated in FIG. 5 and it can be seen that the forward face 17 isformed with orifices 18 I provided with lugs 19 corresponding to thelugs 14 il-' lustrated in FIG. 2. The rear face (not shown) may beunlocked and open only at the analytical laboratory. Such a box, onwhich any information necessary for the identification of the tubes maybe inscribed, ensures perfect safety of manipulation andavoids anyerror. It is also possible to modify the means for gripping the pistonand the shape of the piston, the support or various component elementsof the device according to the invention.

As materials, one may use more particularly inert and resilientsynthetic materials. Thus, by way of nonlimiting example, polyethylene,polystyrene and methyl polymethacrylate are suitable. It is convenientto employ a transparent material, because the filling of the receivingtube can then be readily checked. The piston may consist of rubber orany other appropriate elastomer. The needles preferably consist ofstainless steel..

The simple construction of the apparatus according to the inventionrenders possible an economical use even if it is used only once, whichis generally the case.

An appropriate reactant, for example a few drops of sodium citrate orheparin solution, may readily be previously introduced into receivingtubes. The reactant may also be introduced in the form of granules intothe duct 6 upstream of the piston. The blood dissolves thesegranulesbefore entering the receiving tube and a homogeneous specimen isthus obtained without any agitation being necessary. The apparatusaccording to the invention is particularly easy for use, whereby anyclumsiness on the part of the operator is avoided. The operator mayhimself adjust the speed of withdrawal of the blood to the desired valuefor avoiding any violent action on the blood.

The apparatus according to the invention is preferably suitable fortaking specimens of very varied liquids. This apparatus, previouslyfilled, may also be employed as a distributor, for example for makinginjections or as a drop counter, notably when the withdrawn liquid is toundergo titrations or analyses by the drop method. It makes it possible,notably, to transfer predetermined volumes of liquids withoutwithdrawing the plug, the latter again acting as a piston after havingbeen perforated by the transfer pipette.

lclaim:

1. A suction apparatus for sampling blood or other liquids comprising aliquid receiving tube having an open end and a closed end, a pistonhaving a reduced diameter forward face slidably disposed in the tubewith its forward face directed toward the open end of said receivingtube, said piston having an annular groove thereabout adjacent theforward face and a perforable wall, and a support rod slidably disposedin the tube having a duct extending therethrough, a hollow needledisposed between the rod and piston adapted to perforate the said wallof the piston and connect said duct with a space between the piston andclosed end of the tube, a plurality of spaced resilient arms definingslots between said arms and carried by the rod about the said needle andpressed inwardly by the wall of the tube combining to form a jaw whichgrasps the said groove of the piston whereby said piston is held therebyduring relative movement between the tube and rod, said tube havingrestraining means extending into said slots to prevent complete removalof said piston from said tube, said resilient arms spontaneouslyspringing apart from the groove upon their exit from the open end of thetube thereby releasing the piston from their grasp.

2. The apparatus of claim 1 wherein said restraining means is at leasttwo inwardly directed lugs aligned with a slot between resilient armswhich partially closes the said open end to prevent the piston frompassing therethrough.

3. A plurality of the tube and rod assemblies of claim 1 combined with ameans for supplying liquid comprising a single conduit connected to allof the ducts of the said rods.

4. The apparatus of claim 1 wherein the said hollow perforating needleis carried by the rod.

5. The apparatus of claim 1 wherein the said per-

1. A suction apparatus for sampling blood or other liquids comprising aliquid receiving tube having an open end and a closed end, a pistonhaving a reduced diameter forward face slidably disposed in the tubewith its forward face directed toward the open end of said receivingtube, said piston having an annular groove thereabout adjacent theforward face and a perforable wall, and a support rod slidably disposedin the tube having a duct extending therethrough, a hollow needledisposed between the rod and piston adaptEd to perforate the said wallof the piston and connect said duct with a space between the piston andclosed end of the tube, a plurality of spaced resilient arms definingslots between said arms and carried by the rod about the said needle andpressed inwardly by the wall of the tube combining to form a jaw whichgrasps the said groove of the piston whereby said piston is held therebyduring relative movement between the tube and rod, said tube havingrestraining means extending into said slots to prevent complete removalof said piston from said tube, said resilient arms spontaneouslyspringing apart from the groove upon their exit from the open end of thetube thereby releasing the piston from their grasp.
 2. The apparatus ofclaim 1 wherein said restraining means is at least two inwardly directedlugs aligned with a slot between resilient arms which partially closesthe said open end to prevent the piston from passing therethrough.
 3. Aplurality of the tube and rod assemblies of claim 1 combined with ameans for supplying liquid comprising a single conduit connected to allof the ducts of the said rods.
 4. The apparatus of claim 1 wherein thesaid hollow perforating needle is carried by the rod.
 5. The apparatusof claim 1 wherein the said perforating needle is carried by the piston.6. The apparatus of claim 5 wherein the supporting rod carries aperforable member closing the duct therethrough, the hollow perforatingneedle is carried by the piston and is pointed at each end, one enddisposed to perforate the perforable wall of the piston and the otherend disposed to perforate the said perforable member carried by thesupporting rod.